Question

Compute the mean of the population(ų)2,5,6,7 and 8.

Compute the variance of the population (ò).

Answer 1

The mean of the population

$\mu=E(X)=(2+5+6+7+8)/5=5.6$

The mean of $X^2$:

$E(X^2)=(2^2+5^2+6^2+7^2+8^2)/5=35.6$

The variance of the population

$\sigma^2=Var(X)=E(X^2)-\mu^2=35.6-5.6^2=4.24$